1. Field of the Invention
This invention relates to a combustion apparatus suited for use in various gaslights such as street lamps using gas, as well as other various types of gas equipment.
2. Description of the Related Art
In various gaslights such as street lamps using gas, especially those using gas, a combustion apparatus is used for setting fire to (igniting) and burning the gas. In the combustion apparatus, high voltage for igniting gas and the on-off operation of a solenoid valve for gas supply must be controlled, thus requiring a power supply for such operation. Conceivable types of power supply are alternating-current (AC) power supply and direct-current (DC) power supply.
An AC power supply is not suited for use in combustion equipment used outdoors, such as a gaslight. This is because various problems must be solved, for example, a problem associated with outdoor installation of a gaslight, a difficulty in wiring depending on the spot where a gaslight is installed, and the possibility of an electric shock.
On the other hand, a DC power supply has advantages that high safety is ensured because of low voltage, that there is no restriction on the place of installation because no cords are required for wiring, that there is no influence of line noise since a DC power supply is an independent closed circuit, that no problem is caused by power stoppage, that a DC power supply is subjected to no lightning surge when used outdoors, and that a DC power supply can be installed even in places where AC power supply cannot be used. However, since a street lamp, for example, is lit up throughout the nighttime, the power supply is used for a long period of time every day. In the case of using a battery as the power supply, a battery of long endurance type is large in size, and even if such battery is used, it must be replaced frequently, which is labor-consuming work.
A solar battery, when used as the battery, requires no replacement, but there still arises a problem of whether the solar battery can provide sufficient electric power to actuate the solenoid valve. Taking these into account, the combined use of a secondary battery, which is rechargeable, and a solar battery in particular is considered to be most suitable as the DC power supply. If these power supplies are merely combined, however, it is not always possible to construct the most efficient power supply system for various circuits constituting the combustion apparatus.